I'm having an Entity which has a primary key / id field like the following:
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
This works well. I'm using EclipseLink to create the DDL-Schema, and the column is correctly created like so:
`id` bigint(20) NOT NULL AUTO_INCREMENT
However, I've got several entities for which I do want to specify the PK myself (it's a little application that transfers data from an old database to the new one we're building). If I specify the ID for the POJO (using setId(Long id)) and persist it, EclipseLink does not save it (i.e. the record is saved, but the id is auto generated by eclipseLink).
Is there a way to manually specify the value of a column which has a #GeneratedValue ?
Here some thoughts on the issue:
I tried to work around the problem by not using #GeneratedValue at all, but simply manually define the column to be AUTO_INCREMENTed. However this forces me to manually provide an IDs always, since EclipseLink validates the primary key (so it may not be null, zero, or a negative number). The exception message reads that I should specify eclipselink.id_validation, however this does not seem to make any difference (I annotated #PrimaryKey(validation = IdValidation.NONE) but still got the same message).
To clarify: I'm using EclipseLink (2.4.0) as persistence provider and I can't switch away from it (large portions of the project depend on eclipselink specific query hints, annotations, and classes).
EDIT (In Response to the answers):
Custom Sequencing: I tried to implement my own sequencing. I tried subclassing DefaultSequence, but EclipseLink will tell me Internal Exception: org.eclipse.persistence.platform.database.MySQLPlatform could not be found. But I've checked: The class is on the classpath.
So I subclassed another class, NativeSequence:
public class MyNativeSequence extends NativeSequence {
public MyNativeSequence() {
super();
}
public MyNativeSequence(final String name) {
super(name);
}
#Override
public boolean shouldAlwaysOverrideExistingValue() {
return false;
}
#Override
public boolean shouldAlwaysOverrideExistingValue(final String seqName) {
return false;
}
}
However, what I get is the following:
javax.persistence.RollbackException: Exception [EclipseLink-7197] (Eclipse Persistence Services - 2.4.0.v20120608-r11652): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Null or zero primary key encountered in unit of work clone [de.dfv.datenbank.domain.Mitarbeiter[ id=null ]], primary key [null]. Set descriptors IdValidation or the "eclipselink.id-validation" property.
at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInternal(EntityTransactionImpl.java:102)
...
Caused by: Exception [EclipseLink-7197] (Eclipse Persistence Services - 2.4.0.v20120608-r11652): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Null or zero primary key encountered in unit of work clone [de.dfv.datenbank.domain.Mitarbeiter[ id=null ]], primary key [null]. Set descriptors IdValidation or the "eclipselink.id-validation" property.
at org.eclipse.persistence.exceptions.ValidationException.nullPrimaryKeyInUnitOfWorkClone(ValidationException.java:1451)
...
(stack trace shortened for clarity). This is the same message which I got before. Shouldn't I subclass NativeSequence? If so, I don't know what to implement for the abstract methods in Sequence or StandardSequence.
It may also be worth noting, that simply subclassing (without overriding any methods) the class works as expected. However, returing false in shouldAlwaysOverrideExistingValue(...) will not generate a single value at all (I stepped through the program and getGeneratedValue() is not called once).
Also, when I insert like 8 entities of a certain kind within a transaction it resulted in 11 records in the database (what the hell?!).
EDIT (2012-09-01): I still do not have a Solution for the problem, Implementing my own sequence did not solve it. What I need is a way to be able to not set an Id explicitly (so it will be auto generated) and to be able to set an Id explicitly (so it will be used for the creation of the record in the database).
I tried to define the column as auto_increment myself and ommit #GeneratedValue, however Validation will kick in and not allow me to save such an entity. If I specify a value != 0 and != zero, mysql will complain for a duplicate primary key.
I'm running out of ideas and options to try. Any? (starting a bounty)
This works with eclipselink. It will create a seperate table for the sequence, but that shouldn't pose a problem.
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name="id", insertable=true, updatable=true, unique=true, nullable=false)
private Long id;
GenerationType.AUTO will choose the ideal generation strategy. Since the field is specified as insertable and updateable, a TABLE generation strategy will be used. This means eclipselink will generate another table holding the current sequence value and generate the sequence itself instead of delegating it to the database. Since the column is declared insertable, if id is null when persisting, eclipselink will generate the id. Otherwise the existing id will be used.
If you use TABLE sequencing, then EclipseLink will allow you to override the value (or SEQUENCE if your database supports this, MySQL does not).
For IDENTITY, I'm not even sure that MySQL will allow you to supply your own Id, you might want to verify this. In general I would never recommend using IDENTITY as it does not support preallocation.
There are a few issues with allowing IDENTITY to provide the id or not. One is that two different insert SQL will need to be generated depending on the id value, as for IDENTITY the id cannot be in the insert at all. You may wish to log a bug to have IDENTITY support user provided ids.
You should still be able to get it working with your own Sequence subclass, or possibly MySQLPlatform subclass. You would set your MySQLPlatform subclass using the "eclipselink.target-database" persistence unit property.
Database-centric solution to your problem:
Create an auxiliary, nullable column in your table. It will hold your manually assigned ids:
CREATE TABLE `test_table`
(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`manual_id` bigint(20) NULL,
`some_other_field` varchar(200) NOT NULL,
PRIMARY KEY(id)
);
Map this column to a normal field in your Entity:
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name="manual_id")
private Integer manualId;
Create a trigger that sets the table id to the manual assigned id if it is not null:
DELIMITER //
CREATE TRIGGER `test_table_bi` BEFORE INSERT ON `test_table`
FOR EACH ROW
BEGIN
IF NEW.`manual_id` IS NOT NULL THEN
SET NEW.`id` = NEW.`manual_id`;
END IF;
END;//
DELIMITER;
Always use the manualId when you need to assign a custom id. The trigger will do the magic for you:
testEntiy.setManualId(300);
entityManager.persist(testEntity);
After the database import phase, simple remove the trigger, the auxiliary column and it's mapping.
DROP TRIGGER `test_table_bi`;
ALTER TABLE `test_table` DROP COLUMN `manual_id`;
Warning
If you manually specify an id greater than the current AUTO_INCREMENT value, the next generated id will jump to the value of the manually assigned id plus 1, e.g.:
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (50, 'Something');
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (NULL, 'Something else');
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (90, 'Something 2');
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (NULL, 'Something else 2');
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (40, 'Something 3');
INSERT INTO `test_table` (manual_id, some_other_field) VALUES (NULL, 'Something else 3');
Will wield the results:
+----+-----------+------------------+
| id | manual_id | some_other_field |
+----+-----------+------------------+
| 50 | 50 | Something |
| 51 | NULL | Something else |
| 90 | 90 | Something 2 |
| 91 | NULL | Something else 2 |
| 40 | 40 | Something 3 |
| 92 | NULL | Something else 3 |
+----+-----------+------------------+
To avoid problems it is highly recommended to set the AUTO_INCREMENT column to start with a number greater than all of the existing ids in your previous database, e.g.:
ALTER TABLE `test_table` AUTO_INCREMENT = 100000;
I might be missing something obvious, but why not just define another Entity with the same #Table(name=".....") annotation, with the same fields, but make the id not generated? Then you can use that Entity for the code that copies data from the old DB to the new, and the one with the generated Id can be used for normal creates that require id generation.
I can't tell you if it works with EclipseLink, but we're using Hibernate here and it doesn't seem to mind it.
Using GenerationType.SEQUENCE with PostgreSQL and EclipseLink worked for me.
1) Change
#GeneratedValue(strategy = GenerationType.IDENTITY)
by
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="step_id_seq")
#SequenceGenerator(name="step_id_seq", sequenceName="step_id_seq")
Now, you can call sequence using NativeQuery:
return ((Vector<Integer>) em.createNativeQuery("select nextval('step_id_seq')::int").getSingleResult()).get(0);
and set the returned Id to your Entity before call EntityManager.persist() method.
Hope it's not too late!
Look for Custom Id Generator
http://blog.anorakgirl.co.uk/2009/01/custom-hibernate-sequence-generator-for-id-field/
maybe this could help.
My way (MySql) is deactivate GeneratedValue:
#Id
//#GeneratedValue
#Column(unique = true, nullable = false, columnDefinition ="BINARY(16)")
private UUID id;
And add in Entity:
#PrePersist
protected void onCreation() {
if (id == null) setId(UUID.randomUUID());
}
Now in my code I can do (on service for example):
String clientID = env.getParam("id");
Entity entity = entityRepository.findFirstById(UUID.fromString(clientID));
//is new?
if (entity==null){
entity = new Entity();
entity.setId(UUID.fromString(clientID));//set cumstom ID here
}
Entity entityNew = entityRepository.save(entity); //insert
if (entityNew.getId().equals(entity.getId()) ){
Log.i("OK!")
}
👌
Related
In my table, I have an ID/column that acts as a Primary Key. At the database level, the key is generated by a sequence function. For example, in Oracle, it is something like:
CREATE SEQUENCE SEQ_CUSTOMER
INCREMENT BY 1
START WITH 5
MAXVALUE 999999999999
MINVALUE 5
ORDER;
In MySQL, I believe there is a way to specify an ID/Primary Key so that a value is generated for it (automatically) on insert.
In my case, I have used Hibernate to generate the Java code (based on the DB Table Definition). The problem is that whenever creating a record, Hibernate wants a value to be assigned a value to the Primary Key. It looks like:
#Id
#Column(name = "CUSTOMERID", unique = true, nullable = false, precision = 22, scale = 0)
public BigDecimal getCustomerid() {
return this.customerid;
}
How can I specify (or annotate) the ID so that it will not require a value to be assigned and just allow the key to be generated at the DB level?
TIA
I use the postgresql database.
I have a serial field in one table, the serial field is not primary key, and it is used to allocate port number to avoid duplication, the serial starts from 30001 for example.
I use hibernate to insert table, but the field is always 0.
My sequence description:
last_value | bigint | 30001
start_value | bigint | 30001
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 30001
and my entity java code is:
#Basic
#Column(name = "XXX")
#SequenceGenerator(name="XXX_seq",sequenceName="XXX_seq", allocationSize=1, initialValue = 30001)
#GeneratedValue(strategy=GenerationType.SEQUENCE,generator="XXX_seq")
Because the field is not primary key, so I don't use the #Id.
How should I do?
As #GeneratedValue can only be used with #Id (answered earlier by tom)
Provides for the specification of generation strategies for the values
of primary keys. The GeneratedValue annotation may be applied to a
primary key property or field of an entity or mapped superclass in
conjunction with the Id annotation.
DOC
Solution
You can get max value by query like: it returns you the max used port
Query query = em.createQuery("select max(u.portId) from XXXX u");
List<Long> list = query.getResultList();
return (list.isEmpty() || list.get(0) == null ? maxId : list.get(0));
#GeneratedValue
only works on identifiers (#Id)
You could use:
an Insert Trigger
a separate Table where you store the last used number
Database specific solution (Postgres can have a Sequence on a Column if i'm not mistaken)
Not really JPA but I don't think that can be done automagically by JPA/Hibernate
I am using jooq generated dao's to do a create operation on a table.
The table has a primary key 'id' with type bigserial and the default constraints of not null
CREATE TABLE public.book (
id bigserial NOT NULL,
author varchar(64)
CONSTRAINT book_primary PRIMARY KEY (id)
)
to create a record with jooq i say
Book b = new Book();
b.setAuthor("Eric");
BookDao bd = new BookDao(jooqConfiguration);
bd.insert(b);
This throws a constrain violation exception that id is null.If i set an id such as
Book b = new Book();
b.setId(25);
b.setAuthor("Eric");
BookDao bd = new BookDao(jooqConfiguration);
bd.insert(b);
I do not get the exception but postgres does not generate a value automatically.
The postgres documentation at http://www.postgresql.org/docs/current/static/datatype-numeric.html#DATATYPE-SERIAL says the "Omit the SERIAL column in INSERT, or specify DEFAULT keyword"
How do i configure the jooq generated dao to either omit this column or use a value of DEFAULT
Edit - I am using jooq version 3.3.2 and postgres 8.4. ( The final target is aws redshift. So prototyping on postgres 8.4).
This issue of generated dao's not properly handling handling default values is already present in jooq's list of github issues as https://github.com/jOOQ/jOOQ/issues/2700.
It is fixed in 3.4.0. Migrating to 3.4.0 fixed the issue for me.
answering the question so that other can find it if required.
Till recent time i was using hibernate #Entity annotation to map to database tables.All the primary keys are annotated with #GeneratedValue(strategy = GenerationType.IDENTITY)
I got a scenario where i need to create new schema + migrate data from old schema into new schema.(with few column changes like drop, length and type)
After successful migration of data to new schema tables when i try to insert data using Application its throwing an exception
[ERROR] util.JDBCExceptionReporter DB2 SQL Error: SQLCODE=-803, SQLSTATE=23505, SQLERRMC=1; _NewSchema_._TableName_ , DRIVER=3.51.90
I believe that application is trying to insert rows again with Primary key value starting from 1 because same application is working fine with empty tables.
I want data rows to be inserted with its primary key value as highest value of existing rows primary key .
Any help will be thank full :)
Yes you can do that by altering the table. Alter the table and set starting index for identity column in DB2.
Suppose maximum rows for TBALE_A is 50 and name of identity column is TABLE_ID
ALTER TABLE TBALE_A ALTER COLUMN TABLE_ID
RESTART WITH 51
Your guess is correct, here is my solution, execute the following SQL to give the ID column a specified start position, then your application will work fine.
alter table TABLE_NAME alter column ID set GENERATED BY DEFAULT RESTART WITH 10000;
Hope to help you :)
In case of generation type , IDENTITY, you should look for identity column to be auto incemental.
#GeneratedValue(strategy = GenerationType.IDENTITY) required primary key column to be auto incremental.
I tried running this statement in Postgres:
insert into field (id, name) values (DEFAULT, 'Me')
and I got this error:
ERROR: null value in column "id" violates not-null constraint
I ended up having to manually set the id. The problem with that is when my app inserts a record I get a duplicate key error. I am building a java app using Play framework and ebean ORM. So the entire schema is generated automatically by ebean. In this case, what is the best practice for inserting a record manually into my db?
Edit:
Here is how I'm creating my Field class
#Entity
public class Field {
#id
public Long id;
public String name;
}
Edit:
I checked the field_seq sequence and it looks like this:
CREATE SEQUENCE public.field_seq INCREMENT BY 1 MINVALUE 1 MAXVALUE 9223372036854775807 START 1 CACHE 1;
Edit:
Here is the generated SQL in pgAdmin III:
CREATE TABLE field
(
id bigint NOT NULL,
created timestamp without time zone,
modified timestamp without time zone,
name character varying(255),
enabled boolean,
auto_set boolean,
section character varying(17),
input_type character varying(8),
user_id bigint,
CONSTRAINT pk_field PRIMARY KEY (id),
CONSTRAINT fk_field_user_3 FOREIGN KEY (user_id)
REFERENCES account (id) MATCH SIMPLE
ON UPDATE NO ACTION ON DELETE NO ACTION,
CONSTRAINT ck_field_input_type CHECK (input_type::text = ANY (ARRAY['TEXT'::character varying, 'TEXTAREA'::character varying]::text[])),
CONSTRAINT ck_field_section CHECK (section::text = ANY (ARRAY['MAIN_CONTACT_INFO'::character varying, 'PARTICIPANT_INFO'::character varying]::text[]))
);
CREATE INDEX ix_field_user_3
ON field
USING btree
(user_id);
There is no column default defined for field.id. Since the sequence public.field_seq seems to exist already (but is not attached to field.id) you can fix it with:
ALTER SEQUENCE field_seq OWNED BY field.id;
ALTER TABLE field
ALTER COLUMN id SET DEFAULT (nextval('field_seq'::regclass));
Make sure the sequence isn't in use for something else, though.
It would be much simpler to create your table like this to begin with:
CREATE TABLE field
(
id bigserial PRIMARY KEY,
...
);
Details on serial or bigserial in the manual.
Not sure how the the Play framework implements this.
This works.
insert into field (id, name) values (nextval('field_seq'), "Me");